Document and Entity Information - shares
9 Months Ended
Sep. 30, 2019
Nov. 06, 2019
Cover [Abstract]    
Document Type 10-Q  
Amendment Flag false  
Document Period End Date Sep. 30, 2019  
Document Fiscal Year Focus 2019  
Document Fiscal Period Focus Q3  
Trading Symbol APVO  
Entity Registrant Name APTEVO THERAPEUTICS INC.  
Entity Central Index Key 0001671584  
Current Fiscal Year End Date --12-31  
Entity Filer Category Accelerated Filer  
Entity Small Business true  
Entity Emerging Growth Company true  
Entity Extended Transition Period true  
Entity Common Stock, Shares Outstanding   45,279,244
Entity Current Reporting Status Yes  
Entity Shell Company false  
Entity File Number 001-37746  
Entity Tax Identification Number 81-1567056  
Entity Address, Address Line One 2401 4th Avenue  
Entity Address, Address Line Two Suite 1050  
Entity Address, City or Town Seattle  
Entity Address, State or Province WA  
Entity Address, Postal Zip Code 98121  
City Area Code 206  
Local Phone Number 838-0500  
Entity Interactive Data Current Yes  
Document Quarterly Report true  
Document Transition Report false  
Entity Incorporation, State or Country Code DE  
Security Exchange Name NASDAQ  
Title of 12(b) Security Common Stock, $0.001 par value per share